Question

Helping my sister with her chem hw. Just need to check my answer!

Calculate the kilocalories needed to heat 5.1 kg of water from 22 °C to 27°C
only one sig fig

Answer 1

Q = 25.5 kcal

Explanation:

Remember:

Q = mcΔT

Q = heat (kcal)

m = mass of water (kg)

c = specific heat of water (kcal/(kg°C))

ΔT = change in temperature (°C)

Given:

m = 5.1 kg

c = 1 kcal/(kg°C)

ΔT = 27°C - 22°C = 5°C

Therefore:

Q = mcΔT

Q = (5.1)(1)(5)

Q = (5.1)(5)

Q = 25.5 kcal